• 대한가정학회지
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• 제43권4호
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• pp.31-47
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• 2005

This study is a preliminary investigation into improving the environmental quality of schools. The purpose was to clarify the present conditions and reasons of noise in elementary schools located near airports and roads by noise level measurements and questionnaire surveys of subjective responses. fold measurements on equivalent and instantaneous noise levels, indoor and outdoor, were carried out in 3 schools during the periods 11th~ 13th of February and 2nd~ 7th of July,2003. The respondents were 94 teachers working in the 3 schools. The results were as follows. 1) Indoor noise levels of the 3 schools were 36.g~73 dB(A) in winter, and 46.9~ 91 dB(A) in summer. These values were higher than the indoor noise standard of 50 dB(A), except for the average of equivalent noise levels in winter.2) Outdoor noise levels of the schools were 41.1 ~ 101 dB(A) in winter, and 52.4~ 102 dB(A) in summer. These values were generally inappropriate relative to the standard for environmental noise of 65 dB(A). 3) The respondents showed relatively non- positive responses during school hours for interruptions by environmental noise.4) The frequently checked types of environmental noise of the schools were 'airplane noise','surrounding facilities', and 'traffic noise'. The frequently checked types of damage by environmental noise were 'Interrupting school hours' and 'Interrupting business'.

• 대한한의학원전학회지
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• 제30권2호
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• pp.99-112
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• 2017

Objectives : 28 prescriptions with the name 'Dossi' can be found in Yixuerumen, and all these prescriptions are highly useful due to their clinical effectiveness. Among them, Dossisosihotang has an important role as the essential prescription utilizing harmonizing and releasing formula. Therefore, this paper aims to ponder upon this prescription. Methods : Dossisosihotang's origin and effectiveness were studied, and the findings served as the basis for analyzing the varied forms of this prescription which came about in the later generations in order to consider more detailed usage of this prescription. Results & Conclusions : Dossisosihotang directs its patient to consume sosihotang added with chenpi, shaoyao, chuanxiong, then simmered, and added with three spoons worth of raw wormwood juice. Its origin can be traced back to shachechuifa's 'Sihossanghaeeum,' and it is mainly effective for treating the blood aspect syndrome of lesser yang disease such as women's cold damage and heat entering the blood chamber. In treating the symptom of half-exterior and half-interior, taohua developed prescriptions depending on the syndrome, such as Sihijigyungtang, Sihohamhyoungtang, Samhosambacktang, Siryungtang, Sihosamultang, Sigalhaegitang, and Samhoseoggotang. These prescriptions became widely known for their clinical efficacy, leading to many later generations of clinical doctors to use them.

• Structural Engineering and Mechanics
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• 제74권6호
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• pp.747-756
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• 2020

High-strength concrete (HSC) generally is made with high amount of cement which may release large amount of hydration heat at early age. The hydration heat will increase the internal temperature of slab and may cause potential cracking. In this study, slab specimens with a dimension of 600 × 600 × 100 mm were cast with concrete incorporating silica fume for test. The thermistors were embedded in the slabs therein to investigate the interior temperature development. The test variables include water-to-binder ratio (0.25, 0.35, 0.40), the cement replacement ratio of silica fume (RSF; 5 %, 10 %, 15 %) and fly ash (RFA; 10 %, 20 %, 30 %). Test results show that reducing the W/B ratio of HSC will enhance the temperature of first heat peak by hydration. The increase of W/B decrease the appearance time of second heat peak, but increase the corresponding maximum temperature. Increase the RSF or decrease the RFA may decrease the appearance time of second heat peak and increase the maximum central temperature of slab. HSC slab with the range of W/B ratio of 0.25 to 0.40 may occur cracking within 4 hours after casting. Reducing W/B may lead to intensive cracking damage, such as more crack number, and larger crack width and length.

• 교육녹색환경연구
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• 제12권1호
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• pp.25-34
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• 2013

As the construction industry develops, environmental pollution gets increasingly serious, giving damage including the increase of incidence of respiratory diseases and skin diseases among children with weakened immune systems, rather than adults. In daycare centers, infants and children spending much of their time, have high frequency of contact with the interior floor finish material. However, the majority of the child care centers don not use eco-friendly flooring but ordinary monorium flooring, because the initial investment cost of the eco-friendly flooring is higher than ordinary monorium flooring. Therefore, in this study, life cycle costs including the initial investment cost of the eco-friendly flooring and ordinary monorium flooring were calculated, demonstrating that the eco-friendly flooring is more economical than ordinary monorium flooring in terms of life-cycle cost. In addition, the analysis of the environmental performance also showed the excellence of the eco-friendly floor finishes. It is expected that the use of the eco-friendly floor finishes will increase due to their excellence in the aspect of life cycle cost and eco-friendly performance, through this study.

• 한국주거학회:학술대회논문집
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• 한국주거학회 2009년 춘계학술발표대회 논문집
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• pp.113-117
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• 2009

By statistics in August, 2007, currently Korean motors registration number broke through 16 million units. The demand of motors is being increased as time goes on and the demand of parking lot within apartment complex is increased together. Therefore, it is inevitable to expand underground parking lots. Underground parking lots have relatively weaker environment than the ground and physical/psychological problems as distance far away from the main building, fear for vehicle damage and crimes, impure air, darkness and closed feeling take place. Underground parking lots also occupy a lot of area ratio within apartment complex and have a lot of effects on other facilities. Therefore, underground parking lots are neglected for all that underground parking lots have deep relations with satisfaction for public space within apartment complex. Accordingly, the purpose of the study is to make reference materials when underground parking lots are planned by grasping satisfaction of underground parking lots through inhabitants'mental survey and surveying preferential location and requirements of parking lots.

• 설비공학논문집
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• 제19권3호
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• pp.228-234
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• 2007

Opening an ancient tomb interior can deal fair damage for preservation in long period because of high moisture. In this study, a duct-type HVAC system was installed to preserve an ancient tomb and temperature and humidity was measured to analyze heat environment. Armhole was measured to search whether an ancient tomb receives effects of vibration caused by a duct-type HVAC system. According to the measured data, temperature in an ancient tomb is kept adaptively in conservation regardless of a duct-type HVAC system installation when it rains in summer. The other side, humidity is kept adaptively in conservation when installed duct-type HVAC system. But when it is in natural state, a lot of humidity by dew condensation phenomena. So it needs a duct-type system for an ancient tomb conservation. In the case of vibration, measurement value of 3 satisfy control but Germanic DIN 4150 does not satisfy. Therefore, equip must be such that it can prevent vibration for safety.

• Nuclear Engineering and Technology
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• 제49권4호
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• pp.781-786
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• 2017

The presence of crust on the inner walls of metallic ducts impairs transportation because crust completely or partially hinders the passage of fluid to the processing unit and causes damage to equipment connected to the production line. Its localization is crucial. With the development of the electronic imaging system installed at the Argonauta/Nuclear Engineering Institute (IEN)/National Nuclear Energy Commission (CNEN) reactor, it became possible to visualize crust in the interior of metallic piping of small diameter using real-time neutron radiography images obtained with a low neutron flux. The obtained images showed the resistance offered by crust on the passage of water inside the pipe. No discrepancy of the flow profile at the bottom of the pipe, before the crust region, was registered. However, after the passage of liquid through the pipe, images of the disturbances of the flow were clear and discrepancies in the flow profile were steep. This shows that this technique added the assembled apparatus was efficient for the visualization of the crust and of the two-phase flows.

• Steel and Composite Structures
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• 제25권1호
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• pp.19-34
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• 2017

The widespread damage to steel Moment Resisting Frames (MRFs) in past major earthquakes have underscored the need to understand the nonlinear inelastic behaviour of such systems. To assess the seismic performance of steel MRF, it is essential to model the nonlinear force-deformation behaviour of beam to column joints. To determine the extent of inelasticity in a beam to column joint, nonlinear finite element analysis is generally carried out, which is computationally involved and demanding. In order to obviate the need of such elaborate analyses, a simplistic method to predict the force-deformation behaviour is required. In this study, a simple, mechanics driven, hand calculation method is proposed to obtain the forcedeformation behaviour of strong axis beam to column moment joints. The force-deformation behaviour for twenty-five interior and exterior beam to column joints, having column to beam strength ratios ranging from 1.2 to 10.99 and 2.4 to 22, respectively, have been obtained. The force-deformation behaviour predicted using the proposed method is compared with the results of finite element analyses. The results show that the proposed method predicts the force-deformation behaviour fairly accurately, with much lesser computational effort. Further the proposed method has been used to conduct Nonlinear Dynamic Time History Analyses of two benchmark frames; close correspondence of results obtained with published results establishes the usefulness and computational accuracy of the method.

• Geomechanics and Engineering
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• 제18권5호
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• pp.481-492
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• 2019

Due to the underground openings, the tangentially concentrated stress of the tunnel remains larger at excavation boundary and decreases toward the interior of the surrounding rock with a certain gradient. In order to study the effect of different gradient stress on rockburst, the true-triaxial gradient and hydraulic-pneumatic combined test apparatus were carried out to simulate the rockburst processes. Under the different gradient stress conditions, the rock-like specimen (gypsum) was tested independently through three principal stress directions loading--fast unloading of single surface--top gradient and hydraulic-pneumatic combined loading, which systematically analyzed the macro-mesoscopic damage phenomena, force characteristics and acoustic emission (AE) signals of the specimen during rockburst. The experimental results indicated that the rockburst test under the gradient and hydraulic-pneumatic combined loading conditions could perfectly reflect the rockburst processes and their stress characteristics; Relatively high stress loading could cause specimen failure, but could not determine its mode. The rockburst under the action of gradient stress suggested that the failure mode of specimen mainly depended on the stress gradient. When the stress gradient was lower, progressive and static spalling failure occured and the rockburst grades were relatively slight. On the other hand, shear fractures occurred in rockbursts accounted for increasingly large proportion as the stress gradient increased and the rockburst occurred more intensely and suddenly, the progressive failure process became unconspicuous, and the rockburst grades were moderate or even stronger.

• 방사성폐기물학회지
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• 제19권1호
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• pp.51-58
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• 2021

Chemical decontamination of primary systems in a nuclear power plant (NPP) prior to commencing the main decommissioning activities is required to reduce radiation exposure during its process. The entire process is repeated until the desired decontamination factor is obtained. To achieve improved decontamination factors over a shorter time with fewer cycles, the appropriate flow characteristics are required. In addition, to prepare an operating procedure that is adaptable to various conditions and situations, the transient analysis results would be required for operator action and system impact assessment. In this study, the flow characteristics in the steady-state and transient conditions for the chemical decontamination operations of the Kori-1 NPP were analyzed and compared via the MARS-KS code simulation. Loss of residual heat removal (RHR) and steam generator tube rupture (SGTR) simulations were conducted for the postulated abnormal events. Loss of RHR results showed the reactor coolant system (RCS) temperature increase, which can damage the reactor coolant pump (RCP)s by its cavitation. The SGTR results indicated a void formation in the RCS interior by the decrease in pressurizer (PZR) pressure, which can cause surface exposure and tripping of the RCPs unless proper actions are taken before the required pressure limit is achieved.